OpenBGPD kasutamine OpenBSDga
Allikas: Kuutõrvaja
Sisukord
Sissejuhatus
Internet koosneb võrkude haldajatele usaldatud suurtest võrkudest, mida nimetatakse autonoomseteks süsteemideks (AS - Autonomous System). Üheks oluliseks ülesandeks nende võrkude pidamisel on ruutingute haldamine, reeglina räägitakse võrkude vahel EGP protokolli ja võrgude sees IGP protokolli.
- EGP (Exterior Gateway Protocol) - nt BGP4 (Border Gateway Protocol) protokoll ja implementatsioon OpenBGPD; BGP4 on 2009 aastal praktiliselt ainus levinud EGP
- IGP (Interior Gateway Protocol) - nt OSPF (Open Shortest Path First) protokoll ja impementatsioon OpenOSPFD; OSPF on 2009 aastal tõenäoliselt kõige levinum IGP, lisaks on palju kasutusel IS-IS
Border Gateway Protocol (BGP) kasutusalad
- nn suurte võrkude omavahel ühendamiseks (nt ISP'ide vahelised ühendused)
- kasutaja ühendamiseks võrku mitme erineva ISP ühenduse abil
BGP tööpõhimõte
TODO
Mõisted
- AS numbrid vahemikus 64512 - 65535 ei ole avalikult kasutuses ja on mõeldud privaatseks kasutamiseks.
- stub AS - AS omab ainult ühte ühendust ühe teise AS'iga; AS sees liigub ainult kohalik liiklus (ingl. k. local traffic)
- multihomed AS - AS omab ühendusi enam kui ühe teise AS'iga; AS sees liigub ainult kohalik liiklus
- transit AS - AS omab ühendusi enam kui ühe teise AS'iga; AS sees liigub kohalik liiklus ja teatud tingimustel läbiv liiklus (ingl. k. transit traffic)
eBGP kasutuse eesmärk
Olgu kasutada selliselt seadistatud võrk
- arvutites on seadistatud võrguseadmed
- vaikelüüs on seadistamata
- ip forwarding on sisselülitatud
RNW - 10.2.0.0/24
haapsalu tallinn narva
AS 65101 AS 65102 AS 65103
___ em0 - 192.168.12.101 (r-id) ___ em1 - 192.168.23.102 (r-id) ___
| | | | | |
| 1 |--------------------------------| 2 |--------------------------------| 3 |
|___| 192.168.12.102 - em0 |___| 192.168.23.103 - em0 |___|
| | | em1 - 192.168.37.103 (r-id)
| em1 - 192.168.14.101 | |
| | |
| | |
| | |
| | |
| | |
| em0 - 192.168.14.104 | |
parnu | | tartu |
AS 65104 _|_ em1 - 192.168.45.104 _|_ AS 65105 |
| | | | |
| 4 |--------------------------------| 5 | em1 - 192.168.23.105 |
|___| 192.168.45.105 (r-id)- em0 |___| |
| | em2 - 192.168.56.105 |
| em2 - 192.168.46.104 (r-id) | |
| | |
| | |
| | |
| | |
| | |
| | |
| em0 - 192.168.46.106 | |
_|_ em1 - 192.168.56.106 (r-id) | _|_ em1 - 192.168.37.107
| | | | |
| 6 |----------------------------------' 192.168.67.107 (r-id) - em0 | 7 |
|___|---------------------------------------------------------------------|___|
em2 - 192.168.67.106
voru pihkva
AS 65106 AS 65107
RNW - 10.6.0.0/24
ning eesmärgiks kasutades OpenBSD OpenBGPD tarkvara
- seadistada iga arvutid tööle BGP ruuteritena oma Autonomous System (AS) jaoks (nt AS 65101)
- ruuterid levitavad üle BGP kuuldud ruutinguid
- 10.6.0.0/24 ja 10.2.0.0/24 võrgus töötavad arvutid peavad saama omavahel suhelda (RNW - routed network, ingl. k. ruuditud võrk)
Testvõrgu ettevalmistamine
Tundub, et 2009 aasta suvel on kõige otstarbekam BGP testiks kasutada tarkvara VMware Server v. 2 abil moodustatud virtuaalset keskkonda. Antud juhtumil on WMware keskkonnas seadistatud
- igale ruuterite omavahelisele ühendusele vastav nn hostonly võrk
- igale ruuterile vastav virtuaalne arvuti
- eemalt üle ssh ligipääsuks on tallinn ja voru arvutitele seadistatud lisaks üks sillatud režiimis töötav võrguseade; läbi nende arvutite pääseb seadistama ssh abil ka ülejäänud arvuteid
BGP seadistamine
AS 65101 - Haapsalu
# cat /etc/bgpd.conf
# global configuration
AS 65101
router-id 192.168.12.101
neighbor 192.168.12.102 {
remote-as 65102
descr AS65102
announce all
}
neighbor 192.168.14.104 {
remote-as 65104
descr AS65104
announce all
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
AS 65102 - Tallinn
# cat /etc/bgpd.conf
# global configuration
AS 65102
router-id 192.168.23.102
network 10.2.0.0/24
neighbor 192.168.12.101 {
remote-as 65101
descr AS65101
}
neighbor 192.168.23.103 {
remote-as 65103
descr AS65103
}
neighbor 192.168.25.105 {
remote-as 65105
descr AS65105
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
AS 65103 - Narva
# cat /etc/bgpd.conf
# global configuration
AS 65103
router-id 192.168.37.103
neighbor 192.168.23.102 {
remote-as 65102
descr AS65102
announce all
}
neighbor 192.168.37.107 {
remote-as 65107
descr AS65107
announce all
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
AS 65104 - Pärnu
# cat /etc/bgpd.conf
# global configuration
AS 65104
router-id 192.168.46.104
neighbor 192.168.14.101 {
remote-as 65101
descr AS65101
announce all
}
neighbor 192.168.45.105 {
remote-as 65105
descr AS65105
announce all
}
neighbor 192.168.46.106 {
remote-as 65106
descr AS65106
announce all
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
AS 65105 - Tartu
# cat /etc/bgpd.conf
# global configuration
AS 65105
router-id 192.168.45.105
neighbor 192.168.45.104 {
remote-as 65104
descr AS65104
}
neighbor 192.168.25.102 {
remote-as 65102
descr AS65102
announce all
}
neighbor 192.168.56.106 {
remote-as 65106
descr AS65106
announce all
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
AS 65106 - Võru
# cat /etc/bgpd.conf
# global configuration
AS 65106
router-id 192.168.56.106
network 10.6.0.0/24
neighbor 192.168.46.104 {
remote-as 65104
descr AS65104
}
neighbor 192.168.56.105 {
remote-as 65105
descr AS65105
}
neighbor 192.168.67.107 {
remote-as 65107
descr AS65107
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
AS 65107 - Pihkva
# cat /etc/bgpd.conf
# global configuration
AS 65107
router-id 192.168.67.107
neighbor 192.168.67.106 {
remote-as 65106
descr AS65106
announce all
}
neighbor 192.168.37.103 {
remote-as 65103
descr AS65103
announce all
}
# filter out prefixes longer than 24 or shorter than 8 bits
deny from any
allow from any inet prefixlen 8 - 24
# do not accept a default route
deny from any prefix 0.0.0.0/0
# filter bogus networks
deny from any prefix 169.254.0.0/16 prefixlen >= 16
deny from any prefix 192.0.2.0/24 prefixlen >= 24
deny from any prefix 224.0.0.0/4 prefixlen >= 4
deny from any prefix 240.0.0.0/4 prefixlen >= 4
BGP kasutamine
TODO
Skeem 2
arvuti-4
|
_|_ em0 (ei ole kasutusel)
| |
192.168.17.253 - em1 |___| em2 - 192.168.18.253
/ \
/ \
AS 65123 ..... AS 65213
internet ...
192.168.17.254 - em0 / \ em0 - 192.168.18.254
| |
_|_ _|_
| | | |
ruuter-2 |___| |___| ruuter-3
| |
192.168.15.254 - em1 | | em1 - 192.168.16.254
\ /
\ /
\ ___ /
192.168.15.253 - em1 | | em2 - 192.168.16.253
|___| ruuter-1
| em0 - 192.168.17.17
|
--|-----------|----|---------|-----
_|_ _|_ _|_
| | | | | |
|___| |___| |___|
arvuti-1 arvuti-2 arvuti-3
Ruuterite seadistamine
TODO
